package com.demo.util;

public class EscapeUnescape {

	 public static String escape(String src) {  
	        int i;  
	        char j;  
	        StringBuffer tmp = new StringBuffer();  
	        tmp.ensureCapacity(src.length() * 6);  
	        for (i = 0; i < src.length(); i++) {  
	            j = src.charAt(i);  
	            if (Character.isDigit(j) || Character.isLowerCase(j)  
	                    || Character.isUpperCase(j))  
	                tmp.append(j);  
	            else if (j < 256) {  
	                tmp.append("%");  
	                if (j < 16)  
	                    tmp.append("0");  
	                tmp.append(Integer.toString(j, 16));  
	            } else {  
	                tmp.append("%u");  
	                tmp.append(Integer.toString(j, 16));  
	            }  
	        }  
	        return tmp.toString();  
	    }  
	 
	    public static String unescape(String src) {  
	        StringBuffer tmp = new StringBuffer();  
	        tmp.ensureCapacity(src.length());  
	        int lastPos = 0, pos = 0;  
	        char ch;  
	        while (lastPos < src.length()) {  
	            pos = src.indexOf("%", lastPos);  
	            if (pos == lastPos) {  
	                if (src.charAt(pos + 1) == 'u') {  
	                    ch = (char) Integer.parseInt(src  
	                            .substring(pos + 2, pos + 6), 16);  
	                    tmp.append(ch);  
	                    lastPos = pos + 6;  
	                } else {  
	                    ch = (char) Integer.parseInt(src  
	                            .substring(pos + 1, pos + 3), 16);  
	                    tmp.append(ch);  
	                    lastPos = pos + 3;  
	                }  
	            } else {  
	                if (pos == -1) {  
	                    tmp.append(src.substring(lastPos));  
	                    lastPos = src.length();  
	                } else {  
	                    tmp.append(src.substring(lastPos, pos));  
	                    lastPos = pos;  
	                }  
	            }  
	        }  
	        return tmp.toString();  
	    }  
	}

